... 2).ISO9001, ISO140001 WFB series of non-sealing self-control self-priming pump is to fill the gaps of the first ... , the company uses: "a chain-type multi-faceted pump centrifugal sealing device", and to eradicate the traditional pump packing seal, packing ... particular, used the term "electric air control valve", truly a "one-draining, life-long self-priming." 4, little vibration, low noise, mobile ...